San Francisco, California Air Quality
San Francisco has a median AQI of 33, earning an air quality grade of A — excellent air quality that ranks better than 86% of US cities. Air quality has been improving steadily over the past decade, a positive sign for residents. Particulate matter (PM2.5) is the primary concern, often linked to vehicle traffic, industrial activity, and wildfire smoke. In 2024, San Francisco recorded 254 good air quality days (76% of monitored days).
Population: 3,417,736 • County: San Francisco
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Quick Facts
| Current AQI | 32 — Good |
| Air Quality Grade | A |
| Median AQI (2024) | 33 |
| vs. U.S. Cities | Better than 86% |
| Primary Pollutant | PM2.5 |
| Unhealthy Days/Year | 0 |
| 10-Year Trend | ↑ Improving |
| Data Source | EPA AirNow |
Health Recommendation
Air quality is satisfactory, and air pollution poses little or no risk.
It's a great day to be active outside!
5-Day AQI Forecast
Last 30 Days
Current Pollutant Levels
Real-time data from EPA AirNow
AQI Trend (10 Years)
Air Quality Days by Year
2024 Air Quality Summary
Primary Pollutant Days (2024)
Days when each pollutant was the primary driver of AQI. Learn about pollutants →
Frequently Asked Questions About San Francisco Air Quality
What is the air quality in San Francisco today?
The current AQI in San Francisco is 32, which is rated "Good". Air quality is satisfactory, and air pollution poses little or no risk.
Is air quality in San Francisco getting better or worse?
Air quality in San Francisco has been improving over the past decade. The median AQI dropped from 41 in 2016 to 33 in 2024.
What is the most common air pollutant in San Francisco?
PM2.5 is the primary air pollutant in San Francisco, responsible for the most air quality-impacted days in 2024. Particulate matter can originate from vehicle exhaust, wildfires, and industrial emissions.
How many unhealthy air days does San Francisco have per year?
In 2024, San Francisco had 0 days when air quality was unhealthy or unhealthy for sensitive groups (AQI above 100). There were 254 good days and 80 moderate days out of 334 days monitored.
What air quality grade does San Francisco receive?
San Francisco receives an air quality grade of A, placing it better than 86% of US cities. This grade is based on a median AQI of 33 for 2024, derived from EPA monitoring data.
Air Quality Grade
Better than 86% of US cities
Nearby Cities
Get AQI Alerts
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National Rankings
See how San Francisco compares to every other US city by air quality.
Best Air Quality Cities →All city rankingsRecommended Air Purifiers for San Francisco
Based on your area's air quality (median AQI: 33), we recommend these air purifiers to help protect your health indoors.
RabbitAir MinusA2
Stylish wall-mountable design with customizable artwork panels.
- ✓Adequate for room size
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Other Great Options
Molekule Air Pro
Commercial-grade with patented PECO technology for destroying pollutants.
Blueair Blue Pure 211+
High performance for large rooms with simple operation.
Dyson Pure Cool TP04
Premium all-in-one air purifier and fan with advanced features.
Not sure which air purifier is right for you?
Learn more about different types of air purifiers and how to choose the best one for your needs.
Read our complete buying guide →